Rotate-to-advance catheterization system

ABSTRACT

A system of rotate-to-advance medical devices including catheters, dilators, occluders, stents, suprapubic catheters and camera introducers configured with external screw threads and depending substantially on rotation for means of advancement and emplacement in mammalian genitourinary and gastrointestinal passages and organs.

REFERENCE TO PENDING PRIOR PATENT APPLICATIONS

This patent application claims benefit of

-   -   (1) pending prior U.S. Provisional Patent Application Ser. No.        60/156,218, filed Sep. 27, 1999 by James J. Frassica for        INTRODUCER WITH ROTARY COUPLING FEATURE; and    -   (2) pending prior U.S. patent application Ser. No. 09/448,054,        filed Nov. 23, 1999 by James J. Frassica for ROTATE TO ADVANCE        CATHETERIZATION SYSTEM.

The two above-identified patent applications are hereby incorporatedherein by reference.

FIELD OF THE INVENTION

This invention relates to apparatus and methods for catheterization andrelated treatments of the genitourinary and gastrointestinal passages ofmammals. More particularly, this invention relates to catheters,dilators, occluders, stents, suprapubic catheters, camera introducersand related medical devices subject to being proximally propelled anddirected for advancement and control in mammalian genitourinary andgastrointestinal passages.

BACKGROUND OF THE INVENTION

In most mammals, mucous membranes line all those passages by which theinternal parts communicate with the exterior, and are continuous withthe skin at the various orifices of the surface of the body. The mucousmembranes are soft and velvety, and very vascular, and their surface iscoated over by their secretion, mucus, which is of a tenaciousconsistency, and serves to protect them from the foreign substancesintroduced into the body with which they are brought in contact.

Mucous membranes are described as lining the two primary mammaliantracts, i.e., the genitourinary and the gastrointestinal—and all, oralmost all, mucous membranes may be classified as belonging to, andcontinuous with, the one or the other of these tracts.

Catheterization of any of these bodily passages may at times be usefulor necessary.

Urinary outlet problems have presumably been around for as long ashumans. History has the ancient Chinese using onion stalks to relievepeople of acute urinary retention. Literature refers to such problems asfar back as 206 B.C., more than 2000 years ago. The ancient Romans areknown to have used catheters, which are believed to have been firstinvented by Erasistratus, a Greek doctor in the third century B.C. TheRoman catheters were fine tubes made of bronze. The Roman gynecologistSoranus describes how catheters could be used to push stones out of theway and back into the cavity of the bladder, thus restoring urine flow.Excavations in Pompeii unearthed several bronze catheters. Theseinstruments were well constructed but relatively simple and showed thatcatheter designs changed little from the period of 79 A.D. until around1700 A.D.

However, during the 18^(th) and 19th centuries, catheter constructionbecame more complex, with an intensified search taking place for anappropriate substance that would be at once flexible, non-irritating andfunctional. England, France, and the United States all had individualsand companies deeply involved with urinary catheters during this period.Many variations were produced, but they all caused significant stress onthe patient when these rigid devices were pushed into the urethra. Thefirst practical breakthrough was made by the French using gum elasticcatheters—a catheter that would bend better in the urethral channel andnot scour the mucosa as much in the process.

Charles Goodyear improved upon what the French had produced when hesuccessfully vulcanized crude rubber. The problem of manufacturing aninstrument which was both sufficiently rigid to enable it to be pushedthrough the urethra and into the bladder, and yet flexible enough tonegotiate the path, had at last reached the point of practicality,notwithstanding its shortcomings. At that time, and even to this day, afunctional urethral catheter is frequently defined as being one that isflexible enough to negotiate the bends of the urethra and stable enoughto be pushed through the length of the urethral passage.

The French urologist J. J. Cazenave, with the hopes that his countrywould regain leadership in the catheter field, dedicated 25-30 years ofhis life improving the flexible durable catheter. This effort was in thelate 1800's and Cazenare's catheter, made of decalcified ivory, was adated device, but it nonetheless shows the consistency of the state ofthe art wherein catheters are pushed into and negotiated along theurethral passage toward the bladder.

During the past 300 years or so, intensified catheter developmentefforts were stimulated by professional pride, national pride andfinancial rewards. These efforts yielded many improvements, such aschanges to size, curve shape, materials of construction, smoothness,lubricants, coatings, combinations of materials, physical properties,chemical properties and more—yet all these improvements subscribed tothe basic principle of external push-to-advance catheter deployment.

The catheters of the prior art are generally large and stiff, difficultand uncomfortable to administer, and uncomfortable to wear for extendedperiods of time. There is a degree of skill, tolerance and patiencerequired from medical personnel installing the catheters that takes muchtime, training and practice to learn. The difficulty, discomfort, riskof injury and infection, inhibition and inconvenience of the methods andapparatus of the prior art results in the deprivation, for manypatients, of the freedom to work, play and travel as do unaffectedpeople.

The anatomy of the adult male urinary tract, as illustrated in FIG. 1,has a bladder 4 where urine is collected prior to exiting the body viathe urethra 6. The bladder 4 converges into the urethra 6 at a muscularexit called the bladder neck 5. Approximately the first inch of theurethra 6 lies within the prostate 7, which is a chestnut-sized gland.The next approximately half inch of the urethra passes through theexternal sphincter 8, which is the muscular flow valve that controls therelease of urine. The remaining six inches of the urethra 6 lie in aspongy zone, exiting the body at the meatus 9.

The normal process of emptying the bladder can be interrupted by twocauses. One is bladder outlet obstruction, and the other is failure ofthe nerves linking the bladder to the brain. The most frequent cause ofbladder outlet obstruction in males is enlargement of the prostate glandby hypertrophy or hyperplasia. In older males, it is not uncommon for aprogressive enlargement of the prostate to constrict the prostateurethra. This condition, known as benign prostatic hyperplasia (BPH),can cause a variety of obstructive symptoms, including urinaryhesitancy, straining to void, decreased size and force of the urinarystream and, in extreme cases, complete urinary retention possiblyleading to renal failure.

The most common surgical intervention for BPH, transurethral resectionof the prostate, or TURP, has a lengthy recovery period of up to oneyear, and presents a high operative risk for complications such assexual dysfunction. Up to 10% of those subjected to such surgery areleft with mild to moderate stress incontinence. Approximately 400,000patients in the United States, and approximately 500,000 patientsinternationally, were diagnosed in 1994 with BPH or cancer-inducedbladder outlet obstructions that were sufficiently severe to warrantTURP or alternative surgery, according to industry sources.

Because of the high costs, medical risks and quality of life compromisesassociated with TURP, new technologies have begun to challenge TURP'sposition as the standard treatment for severe BPH. Recently, the U.S.Food and Drug Administration (FDA) approved two drugs, tera zosinhydrochloride and rinasteride, to treat BPH. However, these drugsgenerally do not improve symptoms for six to nine months after treatmentbegins, and are not without side effects.

Urethral strictures are another cause of outlet obstruction, often dueto fibrous tissue growth resulting from reaction to catheters orcystoscopes or from injury, birth defects or disease, and are commonlytreated by urethral dilation, catheterization or surgery. Men withurethral strictures also experience a limited ability to urinate, whichmay cause extreme discomfort and, if left untreated, may causecomplications that necessitate catheterization. Approximately 50,000patients in the United States were diagnosed with recurrent urethralstrictures in 1994, according to industry sources. It is estimated thatapproximately 75,000 additional patients were diagnosed internationally.

Women suffer from urinary incontinence far more often than men and at ayounger age, primarily because of the stress associated with pregnancyand childbirth, the shorter length of the female urethra, and theabsence of a prostate. The U.S. Department of Health and Human Services(HHS) estimates that the involuntary loss of urine affects approximately10 million Americans, of which 8.5 million are women. Seven million ofthese women are non-institutionalized, or community-dwelling.

For women between the ages of 15 and 64, the prevalence of urinaryincontinence is estimated to range from 10 to 25 percent of thepopulation. For non-institutionalized persons over the age of 60, theprevalence of urinary incontinence ranges from 15 to 30 percent, withthe prevalence in women twice that of men.

The involuntary loss of urine can be caused by a variety of anatomicaland physiological factors. The type and cause of urinary incontinence isimportant to how the condition is treated and managed. The two broadcategories of urinary incontinence are urge and stress incontinence.Some people suffer from what is termed mixed incontinence, or acombination of stress and urge incontinence.

Urge incontinence is the involuntary loss of urine associated with anabrupt and strong desire to void. In most cases, urge incontinence iscaused by involuntary detrusor (the smooth muscle in the wall of thebladder) contractions or over-activity. For many people, urgeincontinence can be satisfactorily managed with pharmaceuticals.

The more frequently occurring stress incontinence is the involuntaryloss of urine caused by movement or activity that increases abdominalpressure. The most common cause of stress incontinence is hypermobilityor significant displacement of the urethra and bladder neck duringexertion. A less frequent cause of stress incontinence is intrinsicurethral sphincter deficiency (ISD), a condition in which the sphincteris unable to generate enough resistance to retain urine in the bladder.

Females, and males with no benign prostatic hyperplasia condition, mightalso have the inability to empty their bladder because of the nerveslinking the bladder to the brain. This condition is known as neuropathicbladder, and may occur in a wide variety of conditions which includespina bifida, multiple sclerosis, spinal injury, slipped disc anddiabetes. When these and other problems prevent the bladder fromeffectively controlling urine, there are a number of treatment options.They are catheters, dilators, occluders, and stents.

Indwelling Foley-type Catheters

During continuous catheterization, an indwelling catheter is retained inthe bladder by a water-filled balloon. The indwelling catheter drainsurine continuously from the bladder into a bag which is attached to theleg or bed. The bag has a tap so that the urine can be emptied atintervals. The catheter is usually inserted by a doctor or nurse andchanged about every four to six weeks. But difficulty in placement hasalways been inherent in this design. This is due to the traditional“push to advance” technology which necessitates a relatively stiff,thick-walled catheter to traverse the delicate mucosal-lined urethra.

Often the French (unit of measurement) size of the catheter is dictatedby the need for stiffness to insert rather than the lumen size needed topass urine. A 14 French or smaller Foley catheter is rarely used becausecatheters of this size lack the column strength needed to push thecatheter along the full length of the urethra into the bladder.

The larger French Foley catheters are painful to place, uncomfortablewhen indwelling, and require a highly-skilled care provider to insert.

Intermittent Catheters

During intermittent catheterization, a simple catheter made of plastic,rubber, or metal is inserted by the patient or a helper for just longenough to empty the bladder completely, which is typically about oneminute. These temporary catheters are usually smaller in diameter andstiffer than an indwelling catheter of the same size. This stiffness canmake catheterization difficult in men because the male urethra is longand has an acute bend within the prostate. Also, when the externalsphincter is reached, the sphincter muscle will contract, making passagedifficult. Most patients learn to catheterize themselves and therebygain a large degree of independence. This process is repeated aboutevery 3-4 hours during the day and occasionally as needed at night.

Intermittent catheterization is mainly used by people who areincontinent due to neuropathic bladder. Intermittent catheterization mayalso be utilized by people who cannot empty their bladder because thebladder muscle is weak and does not contract properly.

Suprapubic Catheters

In some patients, an alternate apparatus and method used to maintainlong term drainage of the bladder is the use of a suprapubic tube.

Suprapubic catheterization of the bladder is performed viatransabdominal puncture which enters the body above the pubic arch andis directed into the bladder using ultrasound or fluoroscopy to guidethe trocar introducer and suprapubic catheter. The trocar introducer isthen removed when proper catheter placement within the bladder isconfirmed, leaving the drainage catheter in place.

Long term drainage may require the fixation of the catheter at the skinusing standard adhesive-based interface components to address mechanicalfixation, infection control, and skin compatibility. The distal end ofthe catheter is commonly contained within the bladder by inflatedballoon, or by winged-shaped tip configurations which expand within thebladder, or by pre-shaped curved catheter tips which curl to theiroriginal J-shape when stiffening wire is removed from the catheterlumen.

A problem with this form of distal end emplacement through the bladderwall is that it is only unidirectional; that is, it only resists theinadvertent pulling out of the tip of the catheter from the wall of thebladder, while allowing the catheter to freely pass further into thebladder, and to back out up to the point of the containment structure.This continuing catheter motion in and out of the bladder puncture sitemay irritate tissue and cause infection or other difficulty at thebladder-catheter interface. Urine is especially irritating to most partsof the human body that are outside of the urinary tract.

Dilators

Dilation is accomplished by pushing successively larger urethraldilation tubes through the urethra so as to increase the size of theurethral lumen, a procedure which is painful and traumatic to thepatient. Surgical treatment of strictures involves surgical risks aswell as complications, including infection, bleeding and restenosis,which frequently requires further treatment.

With the exception of balloon catheters, the current art of dilators hasalso changed little over the passage of time. A shaft with an increasingtaper, bulbous structure, or enlarged end is pushed from without thepassage to advance the tool through the restricted passage, thusforcing, by longitudinally-applied pressure, the lateral expansion ofthe passage walls. This push-to-advance method necessitates a stiffshaft which has all the same limitations as traditional catheters.Catheters inherently provide a degree of this dilatorial function to theextent that the passage is opened sufficiently to accommodate thecatheter.

Occluders

Occluders are used in some cases to control incontinence. Occluders ofthe prior art are constructed and applied with the same push-to-advanceconcept as the catheters and dilators described above, and hence sufferfrom the same disadvantages. The basic occluder is a bulb or plug on ashaft which is inserted within the urethra to stop or prevent the normalflow of urine through the urethra, or driven all the way into thebladder, for example, and allowed to seat as a plug at the neck of theurethra to prevent the flow of urine from the bladder.

Stents

A stent is a tubular metallic mesh device that is implanted in to openand support a stricture so as to allow for urine flow. The stent body isbetween 3.5 cm and 6.5 cm in length, depending on the anatomy, and isexpandable by design to anchor in place. The stent, being a mesh, hasopenings that allow the tissue to grow through the wall, making removaldifficult and causing encrustation that reduces urine flow.

Intraurethral Valved Catheters

An intraurethral valved catheter is a device that is implanted tocontrol the flow of urine by means of an integral valve that is remotelyactuated. Since the entire catheter length is within the urethra, thechance for external infection is reduced. The anchoring mechanism ofcurrent designs is accomplished with balloons, or “petal-like”projections from the catheter. Both of the aforementioned designs arecomplicated to install and difficult to remove and, if the valve fails,leaves the patient in a painful and dangerous situation.

Patents In The Prior Art

There has been patent activity in the prior art indicatingdissatisfaction with the push-to-advance methodology. Catheters havebeen adorned with a wide assortment of spiral and threaded featuresdescribed as intended to ease the trauma and pain of what clearlyremained a push-in device. Alvord's U.S. Pat. No. 207,932, Peyret'sFrench Pat. No. 564,832, Hayes' U.S. Pat. No. 1,644,919, and Jacoby'sU.S. Pat. No. 1,888,349 are representative of these. In all cases, thesedisclosures fail to recognize that the basic push-to-advance techniqueis fundamentally flawed and should be abandoned, and fail to resolve thecritical features of structure necessary for rotational advancement as asubstitute for the push-to-advance method.

Other art reveals the use of spiral features for different purposes. Forexample, Spinosa's U.S. Pat. No. 3,815,608 discloses a catheter with athread designed to hold the urethral wall away from the shaft so as toallow urine to flow around the outside of the catheter. Such disclosureslikewise reveal a reliance on push-in methods, or an assumption thatsuch structures can be pulled out without regard to the spiral features,again failing to recognize rotation as a viable substitute for pushing,and failing to resolve the critical features of structure necessary foreffective rotational advancement.

As a further indication of the failure of the prior art to provideeffective improvements to traditional push-in methods, there is noapparent indication among the products commercially available, or in themedical practices known to the applicant, that any of thesespirally-ornamented devices were ever found to be clinically viable.

Gastrointestinal Endoscopes

The current device used for inspection and treatment of the GI(gastrointestinal) tract is a flexible endoscope. This device takes ahigh level of skill to use, is difficult to maneuver and can be verypainful for the patient, due to the basic push-to-advance design thathas not changed since the device was invented in the early 1960's. Thedistal tip of the endoscope typically has the following parts:

-   -   1. a channel opening for suction and passage of accessories;    -   2. a light guide lens to distribute light from a fiberoptic        bundle to illuminate the visual field;    -   3. an objective lens to focus an image of the mucosa onto the        face of an image bundle for transmission back to an eyepiece;        and    -   4. an air/water jet, which supplies air to inflate the organ        being observed, and water to clean off the image (i.e.,        objective) lens.

The so-called “bending section” is the distal end of the tube, rangingfrom approximately 8-15 cm long, which can articulate so as to steer thescope as it is pushed inward and is controlled by a cable mechanism thatis connected to control knobs on the proximal handle.

The so-called “insertion tube”, which makes up the rest of theendoscope's 60-150 cm length, is not capable of controlled deflection.It has a tailored bending flexibility and torque transmission which isof major importance in endoscope design. Most instruments have atwo-stage bending stiffness, i.e., the distal portion of the insertiontube is more flexible than the proximal portion. The flexibility of eachportion of the insertion tube requires extensive clinical testing toensure that the endoscope handles easily and produces a minimum ofpatient discomfort.

The colon is a tubular organ which runs from the cecum in the rightlower quadrant to the rectum. It is widest in the cecum and ascendingcolon and gradually narrows as one approaches the rectum. The colon isdivided into the following sections:

-   -   a. the cecum;    -   b. the ascending colon, which runs cephalad (towards the head)        from the cecum to the hepatic flexure;    -   c. the transverse colon, which runs from the hepatic flexure in        the upper quadrant to the splenic flexure in the left upper        quadrant;    -   d. the descending colon, which runs caudad (toward the feet)        from the splenic flexure to the left lower quadrant;    -   e. the sigmoid colon, which runs from the left lower quadrant to        the rectosigmoid junction; and    -   f. the rectum, which extends down to the anal canal.

The inner layer of circular muscle is present throughout the colon. Theouter longitudinal muscle in the wall of the colon is fined into threebands, the teniae coli. These bands start at the base of the appendixand run in the wall of the colon down to the rectum, where they diffuseinto the muscular coat. The three teniae cause the colon to have atriangular appearance endoscopically; this is especially prominent inthe ascending and transverse colon. The haustra are outpouchings of thecolon, separated by folds. In the descending colon the endoscopicappearance is often tubular.

Most experienced colonoscopists use similar endoscopic techniques. Airis introduced to inflate the colon, but as little as possible to preventoverdistension. The pushing pressure on the endoscope is gentle to avoidstretching the colonic wall or mesentery (the connective tissue thatholds the colon like a fan) which can cause pain, a vagal episode, or aperforation. The lumen is kept in view at all times; little or none ofthe examination is performed blindly, because the colonoscopist ispushing a stiff instrument through delicate tissue.

A variety of in and out maneuvers are used to “accordian” the colon onthe colonoscope, keeping the colonoscope as free of loops as possible.In the difficult colon, special maneuvers such as the creating of analpha loop in the sigmoid colon are used to pass the sharply angulatedsigmoid/descending colon junction. This maneuver may requirefluoroscopic guidance and training in the technique.

The colonoscope is advanced to the cecum under direct visualization. Thedetailed examination of the mucosa is usually performed as thecolonoscope is slowly removed from the cecum.

To inspect the whole length of the large intestine requires a highlyskilled practitioner, which makes the procedure costly. Even still, theprocedure can be very painful for the patient, making sedationnecessary. This is due to the inherent deficiencies in the“push-to-advance” design.

SUMMARY

In summary, there are problems in making present push-in catheters,dilators, and occluders stiff enough for penetration and flexible enoughto make the turns without undue risk of trauma to the wall of thepassageway when being pushed in; and once installed, comfortable enoughto wear for an extended period of time. The problems with stentencrustation and removal are well known. Self-administration isinhibited by all of the short-comings of the prior art. Further injury,infection and discomfort can result from unskilled or impropertechnique. The problems with colonoscopy have been previously described.

The long history of push-in catheters/dilators and occluders hasgradually crystallized into an industry-wide, self-perpetuating,fundamental assumption that catheters are to be mainly pushed throughbodily passageways, albeit with some rotational easing. This “fact” isso widely perpetuated and pervasive in the commercially-availableproducts and medical practices as to have stifled original thinking inthis art. This, in spite of the well-recorded shortcomings of pain,trauma, risk of rupture, and failed, aborted or incomplete procedures,and the need for skilled practitioners and special equipment formonitoring and safeguarding against the inherent problems.

SUMMARY OF THE INVENTION

For the purposes of this disclosure, including the appended claims, theterms “distal”, “distally”, and “distal end”, as they relate to thedevices and methods described herein, refer to the end of the devicefurther from, or in the direction away from, a practitioner who might beapplying the device or method to the subject. Stated otherwise, theaforementioned terms refer to the end of the device closer to, or in thedirection towards, the subject's interior.

The terms “proximal”, “proximally”, and “proximal end”, as they relateto the devices and methods described herein, refer to the end of thedevice closer to, or in the direction towards, the practitioner whomight be applying the device or method, rather than to the subject.

Objects of the invention include providing and employing screw-basedmeans for rotational advancement and anchoring of catheters, probes,occluders, stents, and dilators into genitourinary and gastrointestinalpassageways such as the urethra, ureter, esophagus and fallopian tube,and for the emplacement of suprapubic catheters for draininggenitourinary organs such as the bladder, whereby the subject device isapplied through a natural body orifice or surgically created opening andis drawn through the passage by the longitudinal pull of a helix on thewalls of the passage or organ as the device is rotated.

This technology is a radical departure from the 4000 year oldtraditional “push-to-advance” methodology previously discussed.

Indwelling and Intermittent Catheters

Flexible, thin-wall indwelling and intermittent catheters and relateddevices and delivery stylets, made possible by this rotate-to-advanceform of emplacement, are less traumatic and easier for the medicalpractitioner or patient to use. The catheter of the invention eliminatesthe problems of conventional devices by using helix or rotationaltechnology that provides controlled insertion and flexibility tonegotiate the urethra. The helix design accomplishes a pre-dilatation ofthe passageway at a steady rate that relaxes the sphincter and lessensor prevents spasm. Once placed, the device is anchored by the radialdisplacement and close pitch of the helix, preventing longitudinalmigration due to body movement or fluid flow.

In another embodiment, the helix is located on the shaft under aFoley-type balloon and disappears when the balloon is inflated. Theflexible, reinforced shaft need be only about half the wall thickness ofconventional Foley catheters, which means a smaller outer diameter (OD)catheter can be used. The helix advances the shaft and dilates theurethra as the catheter is inserted. Once the bladder is reached, theballoon is inflated with sterile water, and the helix is engulfed by theballoon. The process is then reversed to remove the catheter. Thistechnology fosters reduced costs for patent care, improved clinicaloutcomes and enhanced patient quality of life.

Continence Catheter With Valve

The continence catheter of the invention, indicated for bladder outletobstructions, is intended for BPH patients who are not able to, orchoose not to, undergo TURP. This embodiment of the invention allows theurethra in the area of the prostate to remain open. At the proximal(external) end of this catheter there may be a flow valve which can bedepressed or otherwise opened to empty the bladder. The catheter may beproduced as a sterile, single-use, disposable item that can be used onceand replaced as needed.

The same embodiment of the catheter of the invention provides a femaleStress UI sufferer with lifestyle benefits that greatly outperformabsorbent products intended to manage this condition.

The patient simply inserts the catheter into the urethral opening androtates the shaft to advance the catheter into the bladder. This can bedone in the morning in the convenience of home. When the user needs tourinate, the valve end of the flexible shaft may be exposed through theclothing and the valve opened to empty the bladder. Since the device isnot removed and reinserted after each voiding, the risk of infection isreduced. At the end of the day, the catheter is easily removed anddisposed of.

Intraurethral Valved Catheter

The male or female intraurethral valved catheter of the invention isindicated for bladder control. This embodiment of the invention allowsthe flow of urine to be controlled by a valve mechanism that is withinthe catheter. This valve may be actuated directly by insertion of a toolsuch as a stylet, or remotely by using a magnetic field device.

The intraurethral device reduces the potential for infection byeliminating the external tubing which can be an entry path for bacterialcontamination. These catheters are typically 3.5 to 6.5 centimeters inlength, depending on the anatomy, and have the helical element of theinvention on the outer diameter of the body. The thread height of thehelix may vary over its length, as an aid to the advancement andretention characteristics of the device. The sidewall of the cathetermay be reinforced to resist collapsing due to contraction pressure. Thiscatheter may be inserted in the urethra under fluoroscopy, using adetachable flexible stylet which keys into the proximal end of thecatheter in a non-rotational fitment, and may be inserted in anoutpatient procedure using topical anesthesia.

Stents

The stent of the invention, indicated for bladder outlet obstructions,keeps the urethra open in the area of the stricture. The stent body maybe between 3.5 cm and 6.5 cm in length, depending on the anatomy, andhas a helical element on the outer diameter of the body to advance andretain the stent. The sidewall of the stent may have a reinforcementmeans to prevent collapsing due to prostate pressure. The stent can beinserted in the urethra under fluoroscopy, using a detachable flexiblestylet which keys into the proximal end of the stent body, and may beinserted in an outpatient procedure using topical anesthesia.

The stents of the invention are not susceptible to being incorporated bythe urethral mucosa in a manner preventing rotation, thereby permittinga lengthy period of emplacement and subsequent removal by the samerotational technique. The stent may also have a sufficiently largeinternal diameter, or lumen, to permit cystoscopies, thereby allowingexamination of the bladder without removing the stent.

Dilators and Occluders

Helically-adapted dilators and occluders of the invention are likewiserotatingly advanced and retracted; the helical element performing adilatory function to some degree. Dilators of respectively largerdiameters may be used to achieve a gradually more pronounced effect.

The rotational advancement means may be combined with thepush-to-advance methodology in any of these devices. In a dilator, forexample, a helically-equipped leader shaft extending distally of thebulbous portion of the device rotatingly advances the device up to thepoint that the helix passes out of the interior end of the passage; theremainder of the leader shaft then providing a guidewire that leads thebulb through the remainder of the passageway when the dilator is pushedfrom the proximal end.

Suprapubic Catheters

The adaptation of the invention to suprapubic catheters, used in aclassic transabdominal puncture for the drainage of the bladder or othergenitourinary organs, permits the helix on the distal end of thecatheter to be emplaced in the wall of the organ far enough so that thehelical vane extends from both sides of the organ wall, so that thelongitudinal sliding motion of the catheter into and out of the organ isinhibited by the helical vane. This reduces a source of irritation andassociated complications at the organ wall entry point.

The helically-adapted suprapubic catheter may be placed in the organusing ultrasound or fluoroscopy to visualize placement, by rotatinglyadvancing the catheter over a guidewire leading to the organ; theguidewire having been installed through a tubular access created byusing a cannula and trocar to reach the organ, the trocar and thecannula having been successively removed.

General Construction

Any embodiment of the invention may be radiopaque, or have radiopaquefeatures, markers or other components, permitting the use of fluoroscopyto monitor emplacement or removal of the device, or even the rotationalorientation and rotational movement of the device.

The thread element may be solid, hollow, or fluid-filled. It may taperin height at various locations to optimize advancement and anchoring.Embodiments or elements of the invention may be fabricated, molded,wound, extruded or otherwise constructed of non-toxic, non-corrosivematerials, or combinations of materials, e.g., a composite construction,that are otherwise tolerant of bodily fluids and/or durable whenimplanted in vivo. Such materials may include, but are not limited to,polyurethane, medical grade stainless steel, silicone, bicarbon,polytetrafluoroethylene, tantalum, titanium, or nickel-titanium alloy.Conversely, materials may be specifically chosen to be bioabsorable soas to obviate the need for removal.

The devices of the invention may be enhanced with one or a combinationof the following coatings: a water-based hydrophilic; antibacterialcoatings such as nitrofurazone; bateriostatic coatings such as silver;or other mediations to further enhance their clinical performance.

Camera Introducer

The threaded camera introducer system, briefly stated, presents a novelmeans for the introduction of visualization sensors and other implementsinto and through the full length of the colon. The fundamental structureof the introducer, consistent with the rotate-to-advance structure andmethodology of the invention, is a large, soft, flexible worm-liketubular device with a helix of soft, pliant threads which translaterotational force at the proximal end to a pulling action on the colonwall.

The hollow core or central lumen connects the distal and proximal endsof the tube. A camera head or other visual sensor can be introduced intothe device and arranged to “see” forward from the center of the bulboustip on the distal end. Light bundles or wires connected to the camerapass through the central lumen and out the proximal end of the device toan appropriate control and viewing apparatus.

The distal end of the device is gently urged into the rectumsufficiently far to engage the helix. The device is rotated from justoutside the point of entry, to slowly advance into and through theentire length of the colon to the cecum. The helical threads pull thedevice gently along the interior colon wall; the flexibility of thedevice allows it to easily negotiate the major turns of the colon. Thelarger threads at the distal end provide the greatest grip or pull, thesmaller threads closer to the proximal end contributing a lesser degreeof grip or pull. The device is removed using the same method in reverse.

As illustrated in the figures, the light bundles or cables may beencased in a flexible torque tube or assembly which provides orcontributes to the torsional strength necessary to rotatingly advanceand withdraw the device.

The interior wall of the main tubular device or introducer may beconfigured to contain the torque tube or vertebra in a non-rotationalmanner, such that torque applied at any place on the exterior wall ofthe introducer is transmitted to the torque tube and hence over the fulllength of the device.

Various embodiments and enhancements are possible, all within the scopeof the invention:

-   -   1. The helical thread or spiral extending the length of the        device may be used for auxiliary purposes, including to:        -   a) carry fluids into the colon/passage;        -   b) provide vacuum to the passageway itself, or vacuum within            the device to facilitate the advancement of the camera or            endoscope into the device;        -   c) convey light bundles or electrical wires for specific            purposes, and/or;        -   d) provide depth markers to assist the practitioner in            determining the general position of the device within the            body;    -   2. the spiral may also be inflated with a fluid during entry to        obtain full thread form and rotationally grip or fix the        catheter to the camera element, and then deflated to permit        non-rotational removal by pulling the device through the colon;    -   3. the video screen, or the image on the screen as seen through        the rotating camera introducer as it advances, may be        electronically processed to hold the image in a non-rotating,        stationary manner for the benefit of the person administering        the procedure;    -   4. the distal portion of the device may be relatively more        flexible to enhance trackability along the path of the        colon/passageway;    -   5. the device may have sufficient torque transmission capability        from the proximal to the distal end so the distal portion of the        device can be thus rotated at full length in the colon without        interior support;    -   6. the distal tip or zone may have a sufficient thread height to        grip the colon wall and provide the primary “pulling power” to        advance the device into the body and negotiate the turns, while        the somewhat lower thread height along the remainder of the        device is adequate to support rotational advancement without        drag and avoid bunching or gathering of the colon wall;    -   7. there are at least three methods of containing and        controlling this 160 cm long instrument to ensure it remains        within the operating field:        -   a) a dispensing device as shown in FIG. 34;        -   b) a straight tubular component; or        -   c) held by an assistant;    -   8. material of construction:        -   a) the main body may be produced from polyvinylchloride            (PVC) plastic and may be reinforced with wire or fabric;        -   b) the helix may be made of PVC and may be reinforced with            wire or otherwise;        -   c) a distal end window may be a flat, optically clear            plastic lens made from PVC, polycarbonate, or acrylic            plastic;    -   9. alternative uses:        -   a) variations on the introducer device within the scope of            the invention include full length tubes, or short sections            analogous to urethral stents, being emplaced in the colon by            the rotational structures and techniques of the invention            for temporary purposes such as to aid in the repair of a            damaged colon or a related abdominal injury or condition, by            providing a supplemental lining and/or form to the colon or            to a section of the colon;    -   10. camera with torque control umbilicus:        -   a) the camera body which houses both the camera and the            light source may be made of stainless steel or molded with a            dimensionally stable plastic such as polycarbonate;        -   b) the vertebrae which makes up the torque control umbilicus            may be made of a high strength thermoplastic or a metal such            as stainless steel or beryllium copper.

By means of the invention, the entire colon can be examined without theneed for a conventional colonoscope or endoscope, and without theattendant expertise, pain, medication, post-procedure recovery time, andcost. The means and method of the invention require less training andhave far greater likelihood of reaching the cecum (far end of the colon)than conventional tools and procedures. Other body cavities andpassageways may be similarly examined.

The camera introducer catheter can be used in four different modes:

-   -   1. as an “introducer”, it includes the following characteristics        and benefits:        -   a) it conveys a camera assembly along the entire colon to            screen patients for polyps, lesions, cancer sights and other            maladies;        -   b) the entire colon can be examined without the need for a            conventional colonoscope/endoscope;        -   c) a total examination of the colon can be successfully            performed with significantly less manipulation technique,            pain, medication and post procedure recovery time;        -   d) it requires less training and has greater success in            reaching the cecum;        -   e) as a single-use disposable device, it allows the            expensive camera with its torque controlled umbilicus to be            used repeatedly without danger of sequential infections;        -   f) the procedure is less expensive when compared to the cost            of cleaning and repairing conventional endoscopes and            amortizing the cost of a costly video processing unit;        -   g) the procedure can be successfully performed by            less-specialized, less-expensive individuals; and        -   h) the “introducer” is supplied sterilized and ready for            use;    -   2. as a more “conventional style endoscope”—by adapting a        conventional endoscope to the structure and method of the        invention, the benefits of the invention are coupled with the        following conventional functions:        -   a) tip articulation;        -   b) air and water delivery;        -   c) suction of fluids;        -   d) illumination of passages;        -   e) imaging capability;        -   f) drug delivery; and        -   g) accessories (e.g., working tools).    -   3. as a “hybrid catheter” having some of the functions and        features of the more “conventional style endoscope” and/or the        “introducer” built into the device for procedure-specific        applications; also, it could be used in conjunction with, or        independent of, conventional endoscopic devices and accessories;        and    -   4. as a “transporter” or “introducer” to deliver a conventional        endoscope to any location of the colon or other passageway—this        may occur by:        -   a) providing a fluid-tight envelope for the endoscope; and        -   b) providing a means for the endoscope to exit the distal            end of the “introducer” to perform diagnostic/therapeutic            procedures normally done with the endoscope.

Still other objects and advantages of the present invention will becomereadily apparent to those skilled in this art from the followingdetailed description, wherein there are shown and described preferredand other embodiments of the invention by way of illustration of thebest mode contemplated for carrying out the invention. As will berealized, the invention is capable of other and different embodiments,and its several details are capable of modifications in various obviousrespects, all without departing from the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of the lower abdominal anatomy of a malesubject, with the threaded portion of the catheter of FIG. 2 extendinginto the bladder;

FIG. 2 is a perspective view of a threaded catheter for a male;

FIG. 3 is a cross-sectional view of the threaded portion of the catheterof FIG. 2;

FIG. 4 is an illustration of the threaded end of the catheter of FIG. 1engaged in the urethra;

FIG. 5 is a perspective view of a threaded catheter for a female;

FIG. 6 is a cross-sectional view of the threaded portion of the catheterof FIG. 5;

FIG. 7 is a perspective view of a threaded catheter and a flexible shaftstylet with which it is installed;

FIG. 8 is a cross-sectional view of the tip of the catheter of FIG. 7,showing the non-rotational fitment that receives the tip of the styletof FIG. 7;

FIG. 9 is a perspective view of the tip of the stylet of FIG. 7 that isinsertable into the fitment of FIG. 8;

FIG. 10 is a diagrammatic, longitudinal cross-sectional view of athreaded balloon catheter showing the thread element inside the inflatedballoon, with lumens shown as dashed lines;

FIG. 11 is a cross-sectional view of the shaft of the catheter of FIG.10, showing the central drain lumen and the smaller inflation lumen;

FIG. 12 is a longitudinal cross-sectional view of the distal end of thecatheter of FIG. 10, showing the balloon contracted around the helicalelement;

FIG. 13 is a side elevation of a threaded dilator;

FIG. 14 is a side elevation of a threaded occluder;

FIG. 15 is a side elevation of another variation of a threaded occluder;

FIG. 16 is a perspective view of a threaded stent, dashed lines showingan internal sidewall reinforcement member and a bushing with a hexagonaldrive socket;

FIG. 17 is a cross-sectional view of the stent of FIG. 16;

FIG. 18 is a proximal end view of the stent of FIG. 16, with thehexagonal drive socket visible at the center;

FIG. 19 is a perspective view of a stylet, with a grip on the proximalend and a hexagonal drive tip on the distal end;

FIG. 20 is a perspective view of the hexagonal drive tip of the styletof FIG. 19;

FIG. 21 is a perspective view of a stent-follower with a helical elementat the distal end;

FIG. 22 is an enlarged, cross-sectional view of the distal end of thestent-follower of FIG. 21, showing the hidden portion of the bushing,with the hexagonal drive aperture in dashed lines;

FIG. 23 is a cross-sectional view of an intraurethral catheter with flowcontrol, showing the coiled wall reinforcement member acting as a springon the ball of the check valve;

FIG. 24 is an enlarged perspective view of a stylet tip for operatingthe check valve of the intraurethral catheter of FIG. 23;

FIG. 25 is a diagrammatic illustration of a suprapubic catheter emplacedthrough the abdomen, with the distal end anchored by the helical threadin the bladder wall;

FIG. 26 is a partial side perspective view of the helical thread of thesuprapubic catheter of FIG. 25, anchored by the helical thread in a holein the bladder wall;

FIG. 27 is a partial front perspective view of the suprapubic catheterof FIGS. 25 and 26 anchored in a hole in the bladder wall, the holebeing stretched and deformed to fit tightly about the tube and thread ofthe catheter;

FIG. 28 is a diagrammatic view of a trocar, cannula and guide wire usedto install the suprapubic catheter of FIG. 25;

FIG. 29 is a distal end view of the suprapubic catheter of FIG. 21,showing rotational orientation markers;

FIG. 30 is a front perspective diagram of a threaded camera introducercatheter advanced into the transverse colon area;

FIG. 31A is a partial side view of the distal end of the catheter ofFIG. 30, showing the larger thread height of the thread in the distalarea of the catheter's length;

FIG. 31B is a partial side view of the mid-section of the catheter ofFIG. 30, showing the reduced thread height of the thread in other thanthe distal area of the catheter's length;

FIG. 32 is a perspective view of a camera assembly with a video cameraor visual sensor head attached to a flexible torque tube or assemblywithin which run electrical cables and/or light bundles;

FIG. 33 is a partial cross-sectional view of the distal end of thepreferred embodiment of FIG. 31A, with the camera assembly of FIG. 32installed as it would be used;

FIG. 34 is a rotating container and dispensing device by which thecatheter of FIG. 30 may be managed and administered during applicationto a patient;

FIGS. 35-39 are schematic views showing various constructions for acamera introducer with rotary coupling;

FIG. 40 is a schematic view of a conduit fitting formed in accordancewith the present invention; and

FIGS. 41-43 are schematic views of an access device formed in accordancewith the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

To those skilled in the art, the invention admits of many variations andappellations in apparatus and methodology. By way of example, there isprovided, in accordance with the present invention, a rotate-to-advancestructure and methodology applicable to a range of medical devices thathave heretofore relied entirely or substantially on a push-to-advancetechnique for penetration of bodily passages. Such devices includecatheters, dilators, and occluders for mammalian genitourinary orgastrointestinal passages such as the urethra or ureter for the usualpurposes associated with such devices where no incising or rupture ofpassage walls or membranes is intended.

Catheters

Referring now to FIGS. 1, 2 and 3, a threaded catheter 101 for males ismade up of a tube 102 with an external thread 103, attachable to a flowcontrol device 104. Tube 102 is extruded from a polyurethane material,has an inside diameter of 0.06 inches, an outside diameter 103 d of0.125 inches, and is approximately 13 inches long. The durometer, asmeasured on the smooth, outside wall of the tube, is 85 Shore A. Distalend 105 is closed off, with its tip rounded to a uniform radius of about0.06 inches. Proximal end 106 of tube 102 is cut off square and attachedto flow control device 104. Tube 102 is sufficiently strong such thatwhen the majority of its length is contained within the urethra, it willwithstand and transmit torque, as applied by finger force at the lowerend of the tube external of the urethra, to the thread.

Referring to FIGS. 2 and 3, external thread 103 is formed from a stripof polyurethane material with a rectangular cross-section of width 103a, 0.05 inches, and height 103 b, 0.032 inches, and continuouslyattached over its length to tube 102, starting 0.2 inches from distalend 105 and extending four complete turns around tube 102 in a clockwisedirection towards proximal end 106 at a uniform pitch 103 c of 0.25inches, resulting in a four-turn thread or helix about one inch long.

It is readily apparent from the dimensions of FIGS. 2 and 3 that thethread height 103 b of catheter 101 is greater than twenty percent (20%)of the 103 d thread diameter. This relative height is desirable toexpand and penetrate the longitudinal folds of the urethra to asufficient depth to achieve a useful grip by the thread.

The diameter of the helix formed by thread 103 of catheter 101 isreferred to as thread diameter 103 d, and is equal to two thread heights103 b plus the outside diameter 102 d of catheter tube 102 or, in thiscase, 2 times 0.032 inches plus 0.125 inches, or approximately 0.19inches. The circumference C of the helix formed by thread 30 iscalculated as H (pi) times thread diameter 103 d or, in this case, 3.14times 0.19, or approximately 0.6 inches.

C=π×thread diameter 103d

The ratio R of thread pitch 103 c, 0.25 inches, to the circumference ofthread diameter 103 d, at 0.6 inches, is much less than 1 to 1, therebyimproving the leverage of the screw thread for converting rotation intolongitudinal pulling power, as compared to ratios larger than 1/1.

$R = \frac{{thread}\mspace{14mu} {pitch}\mspace{14mu} 103c}{C}$

The shoulders of thread 103 have a radius of 0.015 inches. In smallquantities, thread 103 may be attached to tube 102 by wickingtetrahydrofuran (THF) solvent under the thread using a fine hollow tube.Catheter 101 may be molded in large quantities with thread 103 being anintegral part of the molded structure.

Referring to FIG. 4, two drainage ports 107, connecting to lumen 108,are oval in shape, the major axis of the oval being parallel to the axisof tube 102 and about 1.5 times the minor axis, which is about equal tothe diameter of the lumen. The two ports are configured 180 degreesapart radially, and spaced longitudinally to fit between the turns ofthread 103.

Both ends of thread 103 are tapered from zero to full height in one-halfturn of the helix, to facilitate gentle, gradual displacement of urethrawall 2 by thread 103 when catheter 101 is rotated clockwise foradvancement into the urethra and counterclockwise for retraction. Thedifference between thread height 103 b and pitch 103 c shown in FIG. 3is sufficient that the urethra wall 2 does not bridge between adjacentturns of thread 103, but rather is only displaced in a manner closelyconforming to the cross-section of thread 103, thereby providing thelongitudinal grip on urethra wall 2 for advancing and retracting thecatheter.

Referring to FIG. 1, catheter 101 is shown in proper position fordraining bladder 4, after it has been advanced through the urethra 6until the helix passes out of the urethra into the bladder.

It is apparent from the anatomy shown in FIG. 1 that thread 103 must belimited in length to be advanced to any point above the sphincter 8, sothat the sphincter may contract directly onto the smooth, round,exterior of tube 102, thereby preventing leakage around the tube, andfurther constraining catheter 101 from migrating or being forced out ofthe urethra by pressure from urine in the bladder. It is furtherapparent from the anatomy shown in FIG. 1 that there is a limit to thelength of thread 103 on a catheter that can be advanced to a positionabove the sphincter 8, not more than about six turns within the optimalrange of thread pitch, and still fit within the bladder 4 withoutinterference. A limited length of thread 103 also localizes the area ofpulling force to the upper end of catheter 101, thereby assuring thatthe trailing length of the catheter is drawn, not pushed, through thepassage.

A useful alternative embodiment of catheter 101 incorporates the recitedexternal thread 103 for rotational advancement, but provides for thecentral lumen to connect to or terminate in a straight-through oraxially-aligned drainage port at the distal tip of the catheter, similarto the most basic conventional catheters. This is likewise useful fordrainage and also enables the insertion or passage of guidewires orother devices where specific procedures require it.

Referring next to FIGS. 5 and 6, a threaded catheter 111 for females,similar to catheter 101 for males, is made up of a tube 112 with athread 113, attachable to a flow control device 114. Tube 112 isextruded from polyurethane material, has an inside diameter of 0.063inches, an outside diameter 112 d of 0.125 inches, and is approximatelyseven inches long. The durometer, as measured on the smooth, outsidewall of the tube, is 85 Shore A. Distal end 115 is closed off, with itstip rounded to a uniform radius of about 0.06 inches. Proximal end 116of tube 112 is cut off square and attached to flow control device 114.Tube 112 is sufficiently strong such that when the majority of itslength is contained within the urethra, it will withstand and transmittorque, as applied by finger force at the lower end of the tube externalof the urethra, to the thread or helix.

Referring to FIGS. 5 and 6, thread 113 of catheter 111 is formed from astrip of polyurethane material with a rectangular cross-section of width113 a of 0.05 inches and height 113 b of 0.10 inches, attached to tube112 starting 0.2 inches from distal end 115 and extending four turnsaround tube 112 in a clockwise direction towards proximal end 116 at auniform pitch 113 c of 0.25 inches, resulting in a four-turn thread orhelix about one inch long.

It is readily apparent from FIGS. 5 and 6 that the thread height 113 bof catheter 111, at 0.10 inches, is much greater than twenty percent(20%) of tube diameter 112 d, at 0.125 inches. This relative threadheight is desirable in order to expand and penetrate the longitudinalfolds of the female urethra sufficiently far to achieve a useful grip bythe thread.

Similar to the description of threaded catheter 101, the diameter 113 dof the helix formed by thread 113 is equal to two thread heights 113 bplus the diameter 112 d or, in this case, 2 times 0.10 plus 0.125, orapproximately 0.33 inches. The circumference C of the helix formed bythread 113 is calculated as π (pi) times the thread diameter 113 d or,in this case, 3.14 times 0.33, or approximately 1.0 inches. The ratio Rof thread pitch 113 c, at 0.25 inches, to the circumference C, at 1.0inches, is again much less than 1 to 1, thereby improving the leverageof the thread for converting rotation into longitudinal pulling power ascompared to larger ratios.

The shoulders of thread 113 have a radius of 0.015 inches. Catheter 111may be constructed or fabricated by the same means as catheter 101.

Referring to FIG. 5, two side drainage ports 117, connecting to lumen118, are oval in shape, the major axis of the oval being parallel to theaxis of tube 112 and about 1.5 times the minor axis, which is aboutequal to the diameter of the lumen. The two side ports 117 areconfigured 180 degrees apart radially, and spaced longitudinally to fitbetween the turns of the thread.

Referring to FIGS. 5 and 6, the ends of thread 113 are tapered from zeroto full height in three-quarters turn of the helix, to facilitategentle, gradual displacement of the urethra wall by the thread when thecatheter is rotated clockwise for advancement and counterclockwise forretraction. The difference between width 113 a and pitch 113 c issufficient that the urethra wall does not bridge between adjacent turns,but rather is displaced in a manner closely conforming to the profile ofthe thread, thereby providing the longitudinal grip on the urethra wallfor advancing and retracting the catheter, in the same manner as thethread of catheter 101 of FIGS. 2 and 3.

The optimal position for threaded catheter 111 for draining the bladderof a female subject is where it is advanced through the urethra untilthe thread passes out of the urethra into the bladder, similar to howcatheter 101 is illustrated in FIG. 1, but for females.

A detailed method for the self-administration of the appropriaterespective threaded catheter 101 or 111, or other similar threadeddevices, will now be explained.

First, the user assembles materials including a sterile threadedcatheter 101 or 111, a container for urine, soap and water, a watersoluble lubricant (if the catheter is not pre-lubricated), a mirror (forfemales), and tissues. The user will then wash the hands and urethralopening with soap and water, squeeze out a small amount of lubricantinto clean tissue, dip the distal end tip of the catheter into thelubricant, and manually engage the tip of the catheter into the urethralopening (the mirror may be helpful for females to assist in locating theopening).

The user will then gently push and turn the catheter in, far enough toengage the thread about one full turn with the urethra, and then gentlyrotate the tube of the catheter in the direction of the thread,preferably clockwise, to advance the catheter into the urethra untilurine appears in the tube. The user then pauses to drain the bladder,directing the urine into the container, then resumes rotation of thecatheter until it is no longer advanced by the rotation, indicating thatthe thread of the catheter has passed into the bladder and the catheteris in proper position.

The user then places a flow control device on the proximal end of thecatheter and empties the bladder periodically as required. The catheteris removed when appropriate using similar precautions for cleanlinessand containment, by rotating the catheter in a direction opposite thedirection of insertion, presumably counterclockwise.

Referring next to FIGS. 7, 8 and 9, another embodiment of the inventionis illustrated by a catheter 121, which is made up of tube 122 withthread 123 applied in the form of a helix, and utilizing a flexibleshaft stylet 131 as an insertion and retraction tool. Stylet 131 has agrip 133 at its proximal end for turning the device. Tube 122 isconfigured with non-rotational fitment 124 (FIG. 8) near its distal end125 so that stylet 131 can be inserted through the tube's proximal end126, passed up through lumen 128 of tube 122, and the tip 134 of stylet131 engaged with fitment 124 in a manner that allows rotation of grip133 in one direction to rotate catheter 121 for advancement into theurethra, and in the other direction for retraction.

The flexible shaft 132 of stylet 131 is sufficiently strong such thatwhen it is fully inserted into catheter 121, shaft 132 will withstandand transmit torque, as applied by finger force to knurled knob grip 133external of the urethra, to the thread 123. Stylet 131 is removed aftercatheter 121 is installed, and reinserted for retracting the catheterwhen required.

Fitment 124 is an elongated collar with a multi-faceted interior wall,securely anchored within tube 122, and configured to receive, in anon-rotational relationship, tip 134. Tip 134 is configured with acorresponding elongated, multi-faceted exterior shape and rounded end,to readily enter fitment 124. Stylet tip 134 and fitment 124 can bealternatively configured and connected by various means to provide anon-sliding, as well as non-rotational, connection.

Referring next to FIGS. 10, 11 and 12, a threaded Foley-type catheter141 of the invention is made from polyurethane material. Catheter 141comprises a flexible tube 142 with an axial drainage lumen 148 runningfrom a drainage port 149 to its proximal end 146 a, and a thread 143applied to its external surface near its distal end 145 in the manner ofthe threaded catheters previously described. Catheter 141 has athin-walled inflatable elastic balloon 150 encasing the helical thread143 and sealed to tube 142 above and below (i.e., distal and proximalto) the thread 143. Drainage port 149 is located above (or distally)from balloon 150. A smaller inflation lumen 151 within tube 142communicates between inflation port 152 (within the envelope of balloon150) and the distal end 146 b of the catheter. Lumens 148 and 151 areisolated from each other, as indicated by FIGS. 11 and 12.

Balloon 150, when uninflated, is normally contracted tightly abouthelical element 143 as illustrated in FIG. 12, and may be inflated as inFIG. 10 by injecting fluid through lumen 151 and into the balloon cavity153. The flexible tube 142 is of sufficient torsional strength towithstand and transmit rotational finger force, applied at the proximalend of tube 142, to thread 143.

Dilators And Occluders

Referring now to FIGS. 13, 14 and 15, a dilator 201 and occluders 211and 221 are similarly constructed by configuring the upper end 205 of aflexible shaft 202 with a tapered bulb 204 near its distal end, anddisposing thereon one or two sections of thread 203. These threads aresimilar to thread 103 on catheter 101 of FIGS. 2 and 3, wherein theheight of the thread is at least twenty percent (20%) of the diameter ofthe shaft 202, and the ratio of thread pitch to the circumference of thethread diameter at any given point on the bulb or shaft is less than oneto one (1/1). The ends of threads 203 are tapered for ease of advancingand retracting, again similar to the threaded catheter of FIGS. 2 and 3.

Dilator 201, of FIG. 13, is configured with multiple turns of thread 203extending over both ends of tapered bulb 204, and is used to dilate aconstricted passage by being rotatingly advanced and retracted throughthe obstructed area of the passage in the same fashion as the threadedcatheters of the invention.

Occluder 211, of FIG. 14, is configured with two sections of thread 203,leaving the midsection or bulbous portion of tapered bulb 204 smooth andround in order to provide a uniform occluding surface. This occluder isused to plug or constrict a passageway at an interior point, beingrotatingly advanced to and retracted from that point in the same fashionas the threaded catheters of the invention.

Occluder 221, of FIG. 15, is configured with two sections of thread 203,the lower or proximal end thread 203 being disposed on the shaft 202below the tapered bulb 204, leaving the lower tapered end of bulb 204smooth and round in order to provide a uniform occluding surface. Thisoccluder is used to plug a passageway at the interior end neck orentrance, being rotatingly advanced until the tapered bulb passesentirely through the passage while the lower thread remains engaged inthe passage, and being then rotatingly retracted to seat the taperedbulb against the neck of the passage. The occluder is then rotatinglyretracted when appropriate.

Stents And Intraurethral Valve Catheters

Referring now to FIGS. 16-18, a threaded urethral stent 301 made frompolyurethane material has a tube 302 with an external thread 303 ofuniform pitch. Thread 303 is similar to thread 103 of catheter 101 ofFIGS. 2 and 3, wherein the height of the thread is at least twentypercent (20%) of the diameter of the shaft 202, and the ratio of threadpitch to the circumference of the thread diameter is less than one toone (1/1). The ends of thread 303 are tapered for ease of advancing andretracting through a passage. There is an interior shoulder 304 (FIG.17) at the distal end 305 of the stent, and a bushing 307 (FIG. 17) ofrelatively harder material disposed proximal to interior shoulder 304.Bushing 304 has a tapered interior wall 308 extending from the bushing'sfull diameter at one end to a uniform hexagonal aperture 309. Coiledsidewall reinforcement member 310 is secured within stent 301intermediate bushing 307 and interior shoulder 304. Alternativeembodiments may have a section of the thread being tapered to a lesserheight or no height, so as to provide a “waist” for gripping by amuscular zone such as the prostate or sphincter. Also, reinforcementmember 310 could be configured or molded into the sidewall of tube 302.

Referring now to FIGS. 19 and 20, a stylet 331, similar to the stylet131 of FIG. 7, has a flexible shaft 332 with a grip 333 at the proximalend for turning, and a hardened hexagonal tip 334 at the distal endwhich closely fits into aperture 309 of stent 301 in a non-rotationalmanner for emplacement of the stent by the method of the invention. Theflexible shaft 332 of the stylet is sufficiently strong such that whentip 334 is inserted into aperture 309, the shaft will withstand andtransmit torque, as applied by rotational finger force at grip 333, tothread 303.

Referring now to FIGS. 21 and 22, a threaded stent-follower 341 has aflexible tube 342, the lumen 347 (FIG. 22) of which is sized to acceptthe ready insertion of tip 334 and shaft 332 of stylet 331 of FIG. 19.Tube 342 is of sufficient torsional strength to accept and transmitrotational finger force applied at its proximal end 346 to its distalend 345. A thread 343 of uniform pitch, and not more than six turns, isapplied to the external surface of tube 342 near distal end 345. Thread343 preferably conforms to the same twenty percent (20%) “rule” ofthread height to tube diameter, and the ratio of thread pitch to threadcircumference of less than one to one (1/1), as thread 103 in FIGS. 2and 3 as described above. The ends of thread 343 are tapered for ease ofadvancing and retracting.

Referring to FIGS. 17 and 22, bushing 351 (FIG. 22) has a uniformhexagonal aperture 352 which is the same size as aperture 309 in bushing307 of stent 301, and a tapered interior wall 353 extended from its fulldiameter at its proximal end to aperture 352. Bushing 351 also has anexternal tapered tip 354 at its distal end. Bushing 351 is affixedwithin the distal end 345 of tube 342, with tip 354 protruding, suchthat the distal end 345 of stent-follower 341 mates with aself-centering action with the proximal end of stent 301 when the twodevices are brought into contact with approximate axial alignment. Whenstent-follower 341 and stent 301 are thus mated, tip 334 (FIG. 19) ofstylet 331 may be extended through aperture 352 (FIG. 22) and intoaperture 309 (FIG. 17), thereby locking stent 301 and stent-follower 341into a fixed rotational relationship. In this condition, the rotation ofthe proximal end of stylet 331 and stent-follower 341 causes theconcurrent rotation of stent 301, whether to rotatingly advance orretract the stent. Stylet 331 may be withdrawn and stent-follower 341rotatingly retracted, leaving stent 301 positioned at any useful pointwithin a passageway.

Referring now to FIG. 23, threaded intraurethral catheter 361, shown incross-section, incorporates means for flow control. The catheter has atube 362 made from a section of extruded polyurethane tubing material,with thread 363 of uniform pitch and not more than six turns applied toits external surface. Thread 363 preferably conforms to the same twentypercent (20%) “rule” of thread height to tube diameter, and ratio ofthread pitch to thread circumference of less than one to one (1/1), asthread 103 in FIGS. 2 and 3 as described above.

Alternative embodiments may have a section of the thread being taperedto a lesser height or no height, to provide a “waist” for gripping by amuscular zone such as the prostate or sphincter. Also, a portion ofreinforcement member 370 could be configured or molded into the sidewall of tube 362.

There is an interior shoulder 364 at the distal end 365 of catheter 361,and a bushing 367 of relatively harder material disposed proximal tointerior shoulder 304. Bushing 367 has a tapered interior wall 368extending from the bushing's full diameter at one end to a uniformhexagonal aperture 369.

A coiled sidewall reinforcement member 370 and a check ball 371 aresecured between interior shoulder 364 and bushing 367 so that coiledmember 370 holds ball 371 in compression against the upper (proximal)end of bushing 367 in the manner of a check valve, whereby to preventoutward (proximal) flow through the lumen 372 of the stent. Coiledmember 370 may be compressed by upward movement of ball 371, therebyopening the check valve to flow.

Referring next to FIGS. 19, 21, 23 and 24, alternate hexagonal tip 384for stylet 331 has a slightly concave proximal end 385 and flutes 386.When used in conjunction with stent-follower 341 to actuate the checkvalve of catheter 361, tip 384 is adapted to be inserted throughaperture 369 of catheter 361 to push ball 371 upward against coil member370, thereby opening the check valve function and permitting outwardflow of fluid through flutes 386 and aperture 369 and then into andthrough stent-follower 341.

Suprapubic

Referring now to FIGS. and 25-29, the threaded suprapubic catheter 401of FIGS. 25 and 26 is constructed with a flexible tube 402, with a lumen408 connecting axial ports at the proximal end and the distal end, andan external thread 403 of uniform pitch applied at its distal end. Asdescribed previously for catheter 101 of FIGS. 2 and 3, the ratio ofthread pitch 403 c to the circumference of thread diameter 403 d is muchless than one to one (1/1). Tube 402 is of sufficient torsional strengthto accept and transmit rotational finger force, applied at the proximalend, to the distal end. The ends of thread 403 are tapered for ease ofadvancing and retracting the catheter through the abdomen and into thebladder wall.

Referring to FIGS. 26 and 27, relative thread height 403 b, as apercentage of tube diameter 402 d, is greater than in the case ofcatheter 101 of FIGS. 2 and 3; preferably greater than fifty percent(50%). This is because suprapubic catheter 401 is being advanced by therotation of thread 403 along an unlined path through the abdomen, andbeing anchored against longitudinal displacement by the engagement ofpitch 403 c of thread 403 in a hole pierced into the wall of organ 31that must encompass tube 402 plus thread 403 passing through the planeof the organ wall 31. This is distinguished from the longer grippingsurface available in a lined passageway as is the case for the catheter101 of FIG. 4.

Referring to FIG. 28, the method by which suprapubic catheter 401 isdeployed is conventional to the extent that trocar 421 and cannula 422are used with ultrasound or fluoroscopy to create the path throughabdomen wall 21 into the bladder organ 31; trocar 421 is removed andtemporary guidewire 423 is then inserted through cannula 422, extendingfrom outside the abdomen wall 21 to inside the bladder organ 31. Cannula422 is then withdrawn, leaving guidewire 423 as a connecting path,extending from outside the body, passing through the abdominal wall 21,and into the bladder organ 31.

Suprapubic catheter 401 is then threaded over the proximal end ofguidewire 423, and gently started into the abdomen wall 21 with arotating motion of about one turn until thread 403 is firmly engaged.The catheter is then rotatingly advanced along the guidewire through theunlined pathway in the same manner as other threaded devices of theinvention, until thread 403 penetrates the wall of organ 31 about onefull turn, as determined by ultrasound, fluoroscopy or equivalent means.The distal end of catheter 401 is then secured in a non-rotatablefashion to abdomen wall 21 using conventional adhesive means orequivalent means, thereby locking thread 403 at the distal end of thecatheter in position in the wall of organ 31. Guidewire 423 is thenwithdrawn. Threaded suprapubic catheter 401 is then available for use.

Referring to FIG. 29, radiopaque markers 411, embedded at select pointsdisplaced along the perimeter of thread 403, provide the capability forexternal detection and monitoring (through fluoroscopy or other means)of the orientation and movement of the distal end of the catheter.

Camera Introducer

Referring next to FIGS. 30 and 31A, threaded camera introducer catheter500, suitable for an average size adult's colon, consists of a bulboustip 501 connecting to a soft, flexible tube 502 which is about 5 feetlong with a tube diameter 502 d of 1 inch. Lumen 508 extends from theinterior face of a window 511 on the distal end of tip 501, through tip501 and tube 502 to the proximal end of tube 502.

Referring to FIG. 31A, external thread 503, with uniform pitch 502 c of1 inch, begins at the edge of window 511, tapering from nothing to aheight of about 0.16 inches, extending around tip 501 and tapering thereto about 0.32 inches, and continuing proximally for about 6 inches alongtube 502. Referring to FIG. 31B, thread height then tapers from a threadheight of 0.32 inches down to 0.16 inches and continues at this heightto the proximal end of tube 502.

An alternative embodiment of the introducer 500 may have a relativelydiminutive tip, but maintain an external thread of equal or greaterheight and total circumference. Another variation of introducer 500 mayhave thread 503 applied only to the introducer's distal end, the threadterminating after a few turns, analogous to catheter 101 of FIG. 2.

It is readily apparent from the dimensions of the introducer 500 ofFIGS. 31A and 31B that the 0.32 inch thread height of thread 503spanning about 6 inches at the distal end of camera introducer 500 isgreater than twenty percent (20%) of tube diameter 502 d. A relativethread height in the range of 20 percent or more of the cameraintroducer diameter size, appropriate to the subject's size, isdesirable to expand and penetrate the walls of the colon to a sufficientdepth to achieve a useful grip by the thread in accordance with therotate-to-advance technology of the invention. The relatively lowerthread height of the continuing thread is adequate to assist in therotational advancement of the fill length of the device without exertingundue forward pressure on the distal end. It also aids in the easing ofadvancement over the full length of the introducer around and throughthe bends in the colon.

It will be further apparent, consistent with the techniques, structureand methodology of the invention, that the thread pitch 503 c, at oneinch, is much less than the overall circumference of thread 503, therebyproviding the necessary leverage to translate rotational effort at theproximal end to a forward force greater than the friction against thewall of the colon. Simple vector analysis confirms this result.

Referring to FIG. 32, a camera assembly 520 consists of camera 521, withlight lens 522 and image lens 523, attached to a flexible, hollow,jointed spine 531. A cable harness 541, connected to camera 521, passesthrough spine 531, extending out the proximal end and connecting to thenecessary power, control and display equipment. Spine 531 is constructedof a chain of vertebrae 532, connected by universal joints which combineflexibility with torsional strength.

Referring to FIG. 33, camera assembly 520 is shown installed in cameraintroducer catheter 501, with camera 521 secured within tip 501 by setscrew 512, so that the camera views forward through the window. Thecamera assembly and catheter are combined here as a camera introducersystem.

Referring next to FIG. 34, rotating container and dispensing system 550consists of drum 551 with axial opening 552 around which handle 553 isrotatably attached. Catheter 501 is rotatingly dispensed duringapplication by holding handle 553 and rotating drum 551 while catheter501 is being rotatingly advanced in the subject colon.

As will be realized, the invention is capable of other and differentembodiments, and its several details are capable of modifications invarious obvious respects, all without departing from the invention. Theobjects and advantages of the invention may be further realized andattained by means of the instrumentalities and combinations particularlypointed out in the appended claims. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive.

Camera Introducer With Rotary Coupling

In FIGS. 30-34, there is shown a threaded camera introducer catheter 500which may be used to position a camera assembly 520 within a bodypassageway.

However, with the aforementioned assembly of (i) threaded cameraintroducer catheter 500 and (ii) camera assembly 520, camera assembly520 is secured, both longitudinally and rotationally, to threaded cameraintroducer catheter 500, e.g., by means of set screw 512 (FIG. 33).Thus, when threaded camera introducer catheter 500 is rotated so as toadvance camera assembly 520 within the colon, camera assembly 520 isalso rotated. This presents two issues.

First, if camera assembly 520 is rotated during passage through thecolon, the image observed by the medical practitioner (on either a videomonitor or through an eyepiece) will also be rotating. This rotation canmake it difficult for the medical practitioner to effectively use thevisualization provided by the camera assembly during passage through thecolon. At the very least, this rotation makes it difficult for themedical practitioner to maintain their sense of direction (i.e.,up/down/left/right) during deployment. This latter point is significant,since the medical practitioner frequently relies on their sense ofspatial orientation in order to navigate a tortuous passageway such asthe lower GI tract. Stabilizing this image electronically requirescomplex additional circuitry and/or computer software in analready-costly scope and image processor system.

Second, if camera assembly 520 is rotated during passage through thecolon, the camera assembly's umbilage connections (e.g., light,electrical, fluid, etc.) become complex. By way of example but notlimitation, in such a situation, water connections to the distal end ofthe endoscope must be designed to rotate freely about the axis of theendoscope, with a leak-proof seal, etc. Again, this can add significantcost and complexity to an already costly and complex endoscope system.

The aforementioned issues are addressed by a new threaded cameraintroducer catheter which has a rotary coupling at its distal end whichis free to rotate relative to the body of the introducer. This newcamera introducer catheter is installed over the distal end theendoscope, with the distal end of the endoscope being secured to therotary coupling. Due to the fact that the endoscope is attached to thecamera introducer catheter by means of the rotary coupling, the cameraintroducer catheter is free to rotate about its axis while the endoscoperemains rotationally stationary.

This new arrangement allows the camera introducer catheter to rotateabout its longitudinal axis, whereby to advance the introducer (andhence the endoscope) within the colon; at the same time, however,inasmuch as rotation of the camera introducer catheter is nottransferred to the endoscope, the endoscope (and hence all of itsassociated input and output connections) remains rotationallystationary. As a result, the new camera introducer catheter allows themedical practitioner to hold the proximal end of the endoscope in thecustomary manner, i.e., rotationally fixed, yet to deploy the endoscopeusing the rotate-to-advance methodology of the present invention. Thisis a significant advance in the art.

Looking at next at FIGS. 35 and 36, there is shown a threaded cameraintroducer catheter 600 which may be used to position a camera assemblyor endoscope 700 within the colon.

In one form of the invention, camera introducer catheter 600 ispreferably substantially the same as the camera introducer catheter 500described above, except for the provision and use of the rotary coupling605 which will hereinafter be discussed in further detail. Moreparticularly, camera introducer catheter 600 generally comprises a tube610 upon which is formed a helical thread 615. Tube 610 has sufficientrigidity that rotation applied to the proximal end of the tube will betransmitted to the distal end of the tube; at the same time, tube 610also has sufficient flexibility that the tube may bend around curves inthe colon. Furthermore, helical thread 615 has a geometry such that whenthe camera introducer catheter 600 is positioned within the colon,rotation of the proximal end of the catheter will cause helical thread615 to pull the camera introducer catheter 600 along the colon, in therotate-to-advance fashion of the present invention.

As referred to above, camera introducer catheter 600 includes the rotarycoupling 605. Rotary coupling 605 is rotatably attached to the distalend of tube 610, such that the rotary coupling may rotate freely aboutthe axis of the tube while being fixed, longitudinally, to the tube.

Preferably camera introducer catheter 600 is constructed so as tominimize friction between rotary coupling 605 and tube 610 when tube 610is rotated. For example, low friction bushings or bearings may be used,and/or appropriate lubricants and/or coatings may be applied tocontacting surfaces.

The joinder between rotary coupling 605 and tube 610 may be sealed toprevent fluid infiltration. A design addressing this feature may includelabyrinth, point-contact and wiper configurations. See, for example,FIG. 36, where a pair of O-ring seals 620 and 625 seal the constructionagainst fluid penetration.

The camera assembly or endoscope 700 is intended to be secured to rotarycoupling 605 so that the endoscope will be longitudinally fixed tocamera introducer catheter 600 but free to rotate relative to the cameraintroducer catheter. By way of example but not limitation, cameraassembly or endoscope 700 may be mounted to rotary coupling 605 by meansof a set screw 630 which causes a protective ring liner 635 into bindingengagement with endoscope 700. Access to set screw 630 may be through anopening 640 in tube 610.

As a result of the foregoing construction, camera assembly or endoscope700 may be secured to rotary coupling 605 of camera introducer catheter600 whereby, when the camera introducer catheter 600 is thereafterplaced within the colon and the proximal end of the catheter's tube 610is rotated, the distal end of tube 610 will turn, whereby helical thread615 will pull the catheter (and hence endoscope 700) distally along thecolon. At the same time, however, inasmuch as rotary coupling 605 isfree to rotate with respect to tube 610, endoscope 700 will remainrotationally stationary with respect to the rotating catheter. In thisway, endoscope 700 may be advanced within the colon using therotate-to-advance technique of the present invention, without requiringany corresponding rotation of the endoscope itself. As a result, themedical practitioner will be able to maintain effective visualization ofthe colon as the endoscope is advanced within the colon. Furthermore,inasmuch as the endoscope per se does not to rotate, the endoscope'sumbilage connection (e.g., light, electrical, fluid, etc.) aresignificantly simplified.

If desired, threaded camera introducer catheter 600 may be provided withmultiple rotary couplings, with the additional rotary couplings beingpositioned anywhere along the length of catheter 600. By way of examplebut not limitation, and looking now at FIG. 35, a relatively shortintroducer catheter 600 might utilize a pair of rotary couplings, one(i.e., 605) at the distal end of the catheter and one (i.e., 605A) atthe proximal end of the catheter; a longer introducer catheter 600 mightinclude several additional rotary couplings, with the additional rotarycouplings (i.e., 605B) being disposed between the two end rotarycouplings.

Furthermore, if desired, threaded introducer catheter 600 may includedesign features designed to maximize the tortional stiffness of its tube610 while minimizing bending stiffness of the tube. By way of examplebut not limitation, and looking now at FIG. 37, tube 610 may be formedwith a composite construction comprising an inner convoluted orcorrugated tube 645, a braided fiber layer 650 and a flexible outsidelayer 655. Where such a construction is used, one or more low frictionbearings 660 (FIG. 37) may be positioned within the catheter's interiorlumen so as to reduce surface contact with the endoscope (not shown inFIG. 37), where bearings 660 include a protrusion 665 which is adaptedto ride in the helical trough of the convoluted or corrugated tube 645.Alternatively, and looking now at FIG. 38, one or more low frictionbearings 670 may be provided, where bearings 670 include a recess 675for receiving the helical peak of convoluted corrugated tube 645.

The threaded camera introducer catheter 600 may also include a featureto disconnect the rotary coupling 605 from the endoscope while thecatheter 600 is deployed within the body. This disconnect may beeffected via fluid, mechanical, electrical or other means. See, forexample, FIG. 39, where a fluid line 680 is used to expand and deflate abladder 685 so as to selectively bind and release, respectively, theendoscope 700 to and from rotary coupling 605.

It should also be appreciated that threaded introducer catheter 600 maybe used to deploy objects other than an endoscope 700. For example,introducer catheter 600 may be used to deploy other visualizationapparatus (e.g., ultrasound devices) and other objects which haveumbilage associated therewith, e.g., a fluid dispenser apparatus, avacuum snare, surgical instruments, etc.

Apparatus For Brachytherapy And Chemotherapy

The treatment of cancerous growths with Brachytherapy is welldocumented. One approach is to surgically implant radioactive materialinto the cancerous growth in order to position the radiation source asclose as possible to the target tissue. Such implantation can bedifficult and time-consuming to effect. Furthermore, if the needsubsequently arises to modify the radiation dosage or to limit theexposure to only a short time period, the implantation process can bedifficult to reverse.

Thus, in accordance with the present invention, there is provided novelapparatus for effecting Brachytherapy, that is, for directingradioactive material to a target site within the body, while allowingfor easy implantation and removal.

Such novel Brachytherapy apparatus may be cannulated or non-cannulated,depending on the anatomy which is to be targeted.

By way of example but not limitation, in one preferred application ofthe novel Brachytherapy apparatus, the device may be used for thetreatment of prostate cancer where the radioactive material must bedelivered to the region of the affected prostate gland. In this case, itwill generally be desirable to use a cannulated form of the invention.

More particularly, in this case, the novel Brachytherapy apparatus maycomprise a stent such as the stent 301 shown in FIGS. 16-18, along withits associated threaded stent-follower 341 shown in FIGS. 21 and 22, aswell as its associated stylet 331 shown in FIGS. 19 and 20, except thatthe stent includes radioactive materials RM (FIG. 17) incorporated intoits construction. As a result, when Brachytherapy stent 301 is emplacedwithin the urethra adjacent to the target prostate tumor, theBrachytherapy stent may irradiate the tumor so as to effect the desiredBrachytherapy.

By way of further example but not limitation, in another preferredapplication of the novel Brachytherapy apparatus, the device may be usedfor the treatment of breast cancer, where the therapeutic radiation mustbe delivered to the breast. In this case, it may be desirable to use anon-cannulated form of the invention.

More particularly, in this case, the novel Brachytherapy apparatus maycomprise a threaded solid element such as the dilator 201 shown in FIG.13, except that the dilator may include radioactive materials RM (FIG.13) incorporated into its construction. As a result, when Brachytherapydilator 201 is advanced through a mammary canal (accessed through anopening on the nipple) and into the interior of the breast, whereby itmay reside adjacent to a target tumor, the Brachytherapy dilator mayirradiate the tumor.

It is also anticipated that the radioactive materials RM of theaforementioned Brachytherapy stent 301 and/or the aforementionedBrachytherapy dilator 201 may be replaced by a therapeutic agent capableof leaching out of the wall of the delivery device and thereby bedelivered to the target tumor. Additionally, the therapeutic agent maybe coated onto a wall of the delivery device for delivery to the targetregion.

Conduit Fitting

Looking next at FIG. 40, there is shown a conduit fitting 800 which canbe used to provide a quick and effective access to a corporeal conduitsuch as an artery or vein, etc.

Conduit fitting 800 generally comprises a body 805 and an obturator 810.Body 805 has a helical thread 815 formed on its distal end, and anenlarged flange 820 formed on body 805 proximal to helical thread 815. Acentral lumen 825 extends the length of body 805. A fluid valve 830,preferably in the form of one or more deformable seals, is disposed atthe distal end of the device so as to selectively close off lumen 825.

Obturator 810 is sized to fit within, and close off, lumen 825 of body805. In addition, obturator 810 is adapted to drivingly engage body 805,whereby rotation of obturator 810 may be converted into correspondingrotation of body 805. By way of example but not limitation, obturator810 may be drivingly connected to body 805 by an obturator pin 835 whichengages a pair of body ears 840.

In one contemplated manner of use, a small hole is first made into acorporeal conduit, e.g., a blood vessel. The distal end of body 805,with obturator 810 in place, is then inserted into the hole. Next,obturator 810 is turned so as to cause body 805 to turn, whereuponthread 815 will pull the distal end of body 805 into the interior of theblood vessel. Engagement of flange 820 with the outer surface of theblood vessel will prevent further movement of body 805 into the bloodvessel. Engagement of flange 820 can also assist in sealing the bloodvessel against leakage. To this end, flange 820 may comprise a compliantseal and/or may comprise a thrombogenic agent. Obturator 810 may then beremoved; however, blood will not pass out of the proximal end of body805 due to the presence of fluid valve 830. Thereafter, when instrumentsor the like are to be introduced into the blood vessel by means of body805, they may be pushed through the fluid valve 830 and lumen 825.

When access to the blood vessel is no longer required, body 805 may bebacked out of the blood vessel, e.g., by reinserting obturator 810 intobody 805 so that obturator pin 835 engages body ears 840, and thenappropriately turning the distal end of the obturator so as to unscrewbody 805 from the wall of the blood vessel.

Body 805 is preferable absent of perforations so as to minimize anyingrowth of tissue into the body, which may render subsequent removalmore difficult. Additionally, various materials and/or coatings may beused to minimize tissue ingrowth to body 805.

Access Device

Visual examination of the large intestine (colonoscopy) is performed bypassing a colonoscope, retrograge, the entire length of the intestine,starting at the rectum and advancing to the cecum.

Standard practice is to lubricate the colonoscope and the entry site(i.e., the anal sphincter) prior to inserting the colonoscope with acombination of push-and-quarter turn twisting motion.

This insertion can be especially challenging where the patient is notrelaxed and the sphincter muscle is held tightly closed. Hemorrhoids canalso cause discomfort when the instrument is advanced into the analsphincter. Also, to the extent that a helically-threaded introducer(such as the threaded introducer catheter 500 described above) is usedto deploy the endoscope, the presence of the introducer's helicalthreads can add to the challenge of inserting the colonoscope into therectum.

To this end, and looking now at FIGS. 41-43, a novel access device 900is provided. Access device 900 comprises two main elements, a liner 905having a central lumen 907 and an obturator 910 sized to selectivelyclose off lumen 907.

In use, obturator 910 is first positioned in lumen 907 of liner 905, andthen the assembly is inserted into the rectum. Once access device 900 isinserted in the rectum, obturator 910 is removed, thereby providing atubular access into the rectum. Then the colonoscope (with associatedthreaded introducer catheter 500 if desired) can be passed freely intothe rectum.

Liner 905 may or may not have a helical thread or other surface geometryon the exterior of the tube to help advance the liner into the rectum orto help keep it in place. Additionally, liner 905 may be designed with afeature to cause it to split so it can be easily removed from theprocedure site once the colonoscope has entered the rectum.

What is claimed is:
 1. A threaded introducer system for accessing abodily passageway, said introducer system comprising: a flexible tubehaving a distal end and a proximal end, a longitudinal axis extendingbetween said distal end and said proximal end, and a lumen extendingfrom said distal end to said proximal end, said lumen being sized toreceive an object to be transported through the bodily passageway;apparatus for connecting the object received within said lumen to saidtube, said apparatus comprising a rotary coupling attached to said tubesuch that said rotary coupling may rotate freely about said longitudinalaxis of said tube while being longitudinally fixed to said tube; and anexternal thread disposed over said distal end of said tube, saidexternal thread having a sufficient structural integrity, and asufficient surface profile, such that when said tube is disposed in abodily passageway, rotation of said tube about said longitudinal axiswill result in longitudinal motion of said tube along said bodilypassageway.
 2. A threaded introducer system according to claim 1 whereinsaid object comprises visualization apparatus for visualizing structuresdisposed adjacent to said distal end of said tube.
 3. A visualizationsystem for traversing a bodily passageway, said system comprising: aflexible tube having a distal end and a proximal end, a longitudinalaxis extending between said distal end and said proximal end, and alumen extending from said distal end to said proximal end; visualizationapparatus received in said lumen for visualizing structures disposedadjacent to said distal end of said tube, said visualization apparatusbeing attached to said tube such that the visualization apparatus mayrotate freely about the longitudinal axis of said tube while beinglongitudinally fixed to said tube; and an external thread disposed oversaid distal end of said tube, said external thread having a sufficientstructural integrity, and a sufficient surface profile, such that whensaid tube is disposed in a bodily passageway, rotation of said tubeabout said longitudinal axis will result in longitudinal motion of saidtube along said bodily passageway.
 4. Apparatus for effectingBrachytherapy, said apparatus comprising: an elongated element having adistal end and a proximal end, and a longitudinal axis extending betweensaid distal end and said proximal end; radioactive material carried byelongated element; and an external thread disposed over said distal endof said elongated element, said external thread having a sufficientstructural integrity, and a sufficient surface profile, such that whensaid elongated element is disposed in a bodily passageway, rotation ofsaid elongated element about said longitudinal axis will result inlongitudinal motion of said elongated element along said bodilypassageway.
 5. Apparatus according to claim 4 wherein said elongatedelement comprises a tube.
 6. Apparatus according to claim 4 wherein saidelongated element comprises a rod.
 7. Apparatus for effecting therapy,said apparatus comprising: an elongated element having a distal end anda proximal end, and a longitudinal axis extending between said distalend and said proximal end; a therapeutic agent carried by elongatedelement; and an external thread disposed over said distal end of saidelongated element, said external thread having a sufficient structuralintegrity, and a sufficient surface profile, such that when saidelongated element is disposed in a bodily passageway, rotation of saidelongated element about said longitudinal axis will result inlongitudinal motion of said elongated element along said bodilypassageway.
 8. Apparatus according to claim 7 wherein said elongatedelement comprises a tube.
 9. Apparatus according to claim 7 wherein saidelongated element comprises a rod.
 10. A conduit fitting for accessing abodily conduit, said conduit fitting comprising: a body having a distalend and a proximal end, a longitudinal axis extending between saiddistal end and said proximal end, and a lumen extending from said distalend to said proximal end; an external thread disposed over said distalend of said body, said external thread having a sufficient structuralintegrity, and a sufficient surface profile, such that when said tube isdisposed in the wall of a bodily conduit, rotation of said tube aboutsaid longitudinal axis will result in longitudinal motion of said tubeinto said bodily conduit; and a flange disposed on said body proximal tosaid external thread, said flange being adapted to act as a stop toprevent further movement of said body into the bodily conduit when saidflange contacts said wall of the bodily conduit.
 11. An access devicefor accessing a bodily conduit, said conduit fitting comprising: a bodyhaving a distal end and a proximal end, a longitudinal axis extendingbetween said distal end and said proximal end, and a lumen extendingfrom said distal end to said proximal end, said lumen being adapted toreceive a gastrointestinal endoscope therein.